Inductor for hot-air furnaces



Aug. 20, 1929. J. c. BOSTAIN 1,725,388

INDUCTOR FOR HOT AIR FURNACES Filed Nov. 23, 1927 2 Sheets-Sheet l gmentoz JAMES C. Bosmu,

attorney) Patented Aug. 20, 1929.

JAMES C. BOSTAIN, OF GOVINGTON, KENTUCKY.

mnuc'ron ron nor-Am FURNACES.

Application filled November 28, 1927.

This invention relates to a device for use in connection with warm air furnaces and has for its object the provision of a means whereby furnaces either in domestic or other 5 installations may have a very ellicient circu lation of air setup therethrough for a time when the fire is being rekindled and the house is normally quite cold.

Another object is to provide means for efiiciently efi'ec-ting such circulation of :air so that the furnace casing and pipes are speedily freed of cold air andwhereby the heat in the furnace is assisted in its circulation into the rooms without having to overcome the weight of the cold air which usually retards the flow of heat when the fire is started.

Another object is to provide a device for the purpose stated which is adapted, within a short time to induce a full normal circulation of air, whereupon it may be rendered inoperative, permitting the air circulation of the furnace to operate in a normal manner without impediment.

These and other objects are attained by the means described herein and disclosed in the accompanying drawings, in which:

Fig. 1 is a side elevation of a warm air furnace and cold air duct having embodied therein a device of the invention.

Fig. 2 is a view taken on line 2-2 of Fi 1.

Fig. 3 is an enlarged view taken on line 33 of Fig. 1.

Fig. 4 is an enlarged view H of Fig. 2.

Fig. 5 is an enlar ed cross sectional view showing a detail of the mounting of the device.

Fig. 6 is a perspective view of a deflector plate forming a detail of the invention.

In the herein described embodiment of the inventionthe device is installed within a somewhat specially formed cold air stub pipe 8 which is connected in the usual manner at the rear and bottom of a warm air furnace '9 of any approved design.

The furnace may have an outer casing 10 over the inner face of which 'the air passes or moves and becomes heated as it rises to the normal furnace pipes. The cold air stub pipe 8 has suitably spaced side walls 100, a bottom wall 11, and rear wall 12 which may be inclined if desired.

' A collar 13 for connection to a cold air duct '(not shown) may enter the cold air taken on line Serial No. 285,341.

stub pipe 8 either at an angle as shown, or

in a horizontal plane. The duct has an inclined top wall '80 in order to provide for a greater cross sectional area in the duct 8 ,closely adjacent the collar 13 than at its place of connection with the furnace casing 10. Within the enlarged cross sectional area of the cold air stub pipe is disposed an electric motor 15 having propeller type fan blades 16 mounted on shaft thereof. As shown in Fig. 3, the bottom wall 11 of the cold air stub pipe has an aperture 17 disposed substantially centrally thereof to perm1t the supporting base 18 for the motor 15 to extend thercthrough. A heavy pad 19 which may be of felt or other suitable material is secured to the floor 20 by any suitable means such as lag screws '21 or the like. Suitable bolts '22 extend through the pad 19 and the feet of the motor base, thereby eifect-ively mounting the motor in posi tion and avoiding any possible noises or vibration in the body of the cold air duct. The pad 19 substantially closes aperture 17 in wall 11 of the cold air stub pipe. A nozzle member 23 is mounted in the cold air stub pipe forwardly of the motor and fanand has a circular opening 24 spaced from and parallel with the path of the fan blades 16. The diameter of the circular opening 24 is substantially equal to the diameter of the fan. The forward opening '25 of the the rear beneath the circular portion of the nozzle. A bolt 28 extending through the walls 26, 11 and the interposed spacer 27 may also extend through a suitable channel iron 29 which serves to space the bottom wall 11 of the cold air stub pipe from the floor 20, In the forward rectangular opening are provided, in suitably spaced relation a plurality of vertically mounted deflector plataes 30 which may be set at various angles depending upon the size of the furnace casing with which the unit is to be used and which are adapted to be secured in adjusted 1, 3, and 4:. that the free passage of air from the collar 13 to the furnace casing is provided for, and that the air may pass through and around the nozzle 23. Therefore under normal conditions, when the fan is inoperative, there is no impediment to the circulation of cold air in the furnace.

. The spacing of the fanv from the circular rear opening 2% of the nozzle is essential to avoid churning of the air Within the cold air stub pipe 8 and to avoid vibration of the nozzle. By means of this arrangement all noise or vibration is eliminated.

A suitable door 34 serves to provide ac cess to the mot-or through a hand-hole in the inclined top 80, of the cold air stub pipe.

In this way the motor may be oiled or given such attention as it may require without disturbing the arrangement of the parts.

The operation of the device is as follows: The parts are mounted as shown in Figs. 1 and 2 when the device is installed, and the deflectors 30 are arranged at suitable angles to the relation of the contour of the wall 33 of the ash pit at that time. Assuming now that the house is cold and the fire is low and that it is desired to kindle the fire and rapidly heat the house; the fan motor would be started by closing an electrical switch, not shown, and located in any place suitable to the operator. The furnace casing, pipes and rooms are at this time filled with cold air so that there is substantially no'circulation of air through the furnace and its pipes. The fan now draws air from the cold air shaft through the collar 13 and into the cold air stub pipe and drives it through the nozzle 23 which directs it downwardly to the base of the furnace casing and distributes it over substantially the entire open area therein. This has the effect of inforcing circulation around allsides of the fire p0; and casing, so that as soon as the lire pot and radiator begin to warm, that warmth is carried into-the rooms by the inforced circulation. Inasmuch as efficiency in a warm air furnace depends upon the rapid movement of air over all warm and hot surfaces, it will be appreciated that by this inducedflow ,of air over all of the surfaces there will be effected started, is to direct a blast of air through the nozzle only. However as soon as warm air begins to pass from the furnace and a natural circulation is induced the air continues to flow through the nozzle and an additional flow is also induced through the cold air stub pipe 8 between the outer walls of the nozzle and the inner Walls of the cold air stub pipe. The fan may be allowed to run for a very short time after this whereupon it may be shut down-so that the flow of air continues through the nozzle and around the exterior thereof in the normal Way in ample volume to prevent overheating of the furnace and burning out of the fire pot bowl. As previously explained the deflectors are initially adjusted to a given installation and are not normally subject to further adjustment or manipulation. The foregoing described device serves to assist in speedily heating the house after it has become chilled and is very effective in serving to carry away the heat from the furnace parts to preclude overheating and burning thereof. This constant full circulation which is brought about by the fan and nozzle induces a natural increased circulation which continues for a number of hours after the fan is shut off. It will be readily understod that a saving in fuel is attained inthis way because all of the heat is carried to the rooms and none of the heat is lost'in the basement or in overheated parts of the furnace.

While the herein disclosed embodiment represents one practical means for carrying out the invention, it will be understood that modifications may be made within the spirit of the invention and the scope of the appended claims.

What is claimed is:

1. The combination with a warm air furnace casing, of a cold air stub pipe connected to the casing and having a cross sectional area intermediate its ends greater than the cross sectional area thereof at its point of communication of the furnace casing, a nozzle disposed in the cold air stub pipe and terminating atv the point of communication between said stub pipe and casing, a motor actuated propeller fan disposed in the inlarged portion of the cold air stub pipe, the fan being spaced from the rear end of the nozzle, the walls of the nozzle being spaced from the walls of the cold air stub pipe and means in the forward end of the nozzle for directing air from the nozzle to the entire area of the bottom of the furnace casing.

2. The combination with a furnace casing having air heating space therein, of a cold space, a nozzle within the stub pipe and spaced from the interior walls thereof whereby to permit of unobstructed flow of air through the pipe and nozzle, said nozzle having a circular open inlet end and a relatively fiattenedand widened discharge end,

and a propeller fan mounted in spaced relation to the circular inlet. end of the nozzle for forcing an air current through said nozzle whereby the forced air current is directed over the bottom of the furnace casing for effecting complete and continuous force displacement of the air in the heating space in the casing while the fan is in operation.

3. In a device for inducing forced air circulation in a warm air furnace the combination of a cold air inlet stub pipe downwardly inclined toward its discharge end, a nozzle member disposed within and spaced from the walls of the inlet stub pipe, said nozzle having a circular inlet end and a flattened rectangular discharge end of a capacity approximately equal to that of the inlet end, a propeller fan spaced at a distance from the inlet end whereby to provide free and unobstructed nor-mal passage of air through and about the nozzle when the fan is inoperative, said fan when actuated serving to force air through the circular opening in the nozzle, the discharge end of the nozzle serving to direct the blast of forced air circulation downwardly and outwardly of the discharge end of the air inlet stub pipe.

4. The combination of a warm air furnace casing of a cold air stub pipe communicat ing with the casing at the bottom thereof, a nozzle within the pipe and having sides laterally divergent and a top sloping downwardly toward and terminating at the cas ing and power means for forcing a volume of air through the nozzle.

5. As a new article of manufacture an air volume directing nozzle for warm air furnaces and the like comprising a hollow member having a circular opening at one end for cooperation with a. volume moving fan and having its sides and top respectively sloping outwardly and downwardly to provide a discharge opening of substantially rectangular form and of an area a proximately equal to that of the circular en opening.

6. In combination a cold air stub pipe for connection with a furnace casing, a nozzle member having a downwardly sloping top and outwardly divergent sides, the cold air pipe having its walls spaced from and approximately parallel to those of said nozzle, means for directing a forced volume of air into the nozzle, said nozzle discharging the air inlike volume but directing it downwardly and outwardly of the nozzle and means to regulate the range of outward distribution of the air.

7. The combination with a warm air furnace comprising a casing, an ash pit and fire box structure substantially concentric with the casing, of a cold air pipe, a nozzle within the pipe and having a discharge end at the wall of the casing, said nozzle having a top wall and side walls arranged to direct a forced volume of air downwardly and outwardly over the entire bottom area of the furnace casing to effect complete displacementof all. the air in said casing and means to preclude impingement of the air Volume directly on the ashpit and firebox structure.

8. The combination with a furnace casing of a cold air inlet, a Volume moving air fan, a nozzle adjacent the fan to receive the air volume without condensation, said nozzle being arranged to direct the volume of air downwardly and outwardly over the entire bottom area of the casing to effect complete and continuous displacement of air in the casing.

In testimony whereof, I have hereunto subscribed my name this 14th day of November, 1927.

JAMES C. BOSTAIN. 

